Socket 479

Socket 479

Type	PGA-ZIF
Chip form factors	Flip-chip pin grid array (FC-PGA2)
Contacts	479 on the socket, 478 on the processor
FSB protocol	AGTL+
FSB frequency	400 MT/s, 533 MT/s
Processors	Intel Pentium M Intel Celeron M VIA C7-M
This article is part of the CPU socket series

Socket 479 is the CPU socket for the Intel Pentium M and Celeron M, mobile processors. Normally used in laptops, but has also been used with Tualatin-M Pentium III processors. The official naming by Intel is µFCPGA and µPGA479M. Despite the fact that Socket 479 has 479 pin holes, the Pentium M Processors for this socket have only 478 pins.

There existed three electrically incompatible, but physically identical, versions of this socket:

• for Pentium III-M (released in 2001);
• for Pentium M and Celeron M 3xx (this was the most common version of the socket, and was released in 2003); and
• a version compatible with Socket M for Intel Core, Core 2 and Celeron M 4xx and 5xx processors.

Technical specifications

This socket is physically similar to, yet different from Socket 478. The Socket 479 has a different electrical pin-arrangement from Socket 478, making it impossible to use a Pentium M in a normal 478 board although the Pentium M fits mechanically in a Socket 478. For this reason manufacturers like Asus have made drop-in boards (e.g. CT-479) which let you use Socket 479 processors.

Chipsets which employ this socket for the Pentium M are the Intel 855GM/GME/PM and Intel 915GM/GMS/PM. While the Intel 855GME chipset supports all Pentium M CPU's, the Intel 855GM chipset does not officially support 90 nm 2MB L2 cache (Dothan core) models (even though it works, it only works at 400FSB, some 3rd party/user was able to overclock the FSB on 855GM/GME/PM to support 533FSB Dothan Core)... The other difference is the 855GM chipset graphics core runs at 200 MHz while the 855GME is runs at 250 MHz.

Asus CT-479 adapter	A comparison of the Dothan (Pentium M SL7SM) (left) and Yonah (Core Duo) (right). Both chips have 478 pins, but the placement of one pin has been changed.

In 2006, Intel released the successor to Socket 479 with a revised pinout for its Core processor, called Socket M. This socket has the placement of one pin changed from the Pentium M version of Socket 479; Socket M processors will physically fit into a Socket 479, but are electrically incompatible with most versions of the socket. Socket M supports a 667 MT/s FSB with the Intel 945PM/945GM chipsets.

See also

• List of Intel microprocessors
• List of Intel Pentium M microprocessors
• List of Intel Celeron microprocessors